Improved machine for forming screw-threads on sheet-metal caps



fvnesses f N-IPUERS. PROM-LITHOGRAPHER WASHINGTON D G i .i i wir.,

TllOMAS HOUGHTON, OF PHlLADELPHIA, DENNSYLVANIA, ASSIGNOR TO S. B.ROWLEY.

IMPROVED MACHINE FOR FOR-MING SCREW-THREADS 0N SHEET-METAL CAPS.

Specification forming part of Letters Patent No. 95, l l 3, datedSeptember 21, 1869.

To all ,whom 'it may concern:`

Beit known that I, THoMAs HoUGHroN, of the cityand count-yofPhiladelphia, andState of Pennsylvania, have invented a new and usefulDevice for Swaging Screw-Threads on Articles of Malleable Metal; and Ido hereby declarethe following to be aclear and exact description of thenature thereof', sufficient to enable others skilled in the art to whichmy invention appertains to fully understand and use the same, referencebeing had to the accompanying drawings, making part of thisspecification, in which- Figur'e 1 is a top view of the deviceillustrating myiinvention. Figs. 2 and 3 are side views thereof. Fig. 4is an end View thereof. Figs. 5,6, 7,8, and 9 are views of detachedparts thereof.

Similar letters of reference indicate corresponding parts in the severalgures.

My invention is a novel device for swaging screw-threads on sheet metalcylinders, caps or rings, and other articles; and it consists in i meansfor advancing the threading-rollers against the blank resting-in thedies and the automatic returnrthereof, the blank being meanwhile heldand released by a peculiar holder and then readily withdrawn in acomplete and perfect state. These results are accomplished by aningenious mode of throwing the proper pulleys in and out of gear in amanner as will be hereinafter more fully described. v

In the drawings, A represents atable or bed, supported upon suitablelegs or feet a, and from which arise standards A', supporting a hollowshaft or mandrel, B, having a longitudinal groove, b. B is a toothedwheel mounted on the mandrel and provided with a` key tting into thegroove b, whereby the mandrel may be longitudinally moved, yet always berotated by the wheel B'.

To one end of the hollow mandrel B, I secure a swaging head or chuck, C,consisting of a suitable disk of metal carrying grooved rollers D, whichare mounted on screw-rods a', placed within eccentric bushings insuitable openin gs in the head C. The heads of the screw rods are flushwith the outer face of the rollers D, and the screw ends receivetightening-nuts d, whose inner faces are concave, so as to clear thebushing-yet have their edges to come in contact with the head, andthereby hold tightly the screw-rods without disturbing the bushing. rlherollers 'D are arranged on sides opposite to each other at the outerface of the head C and are let into the same so that one face of eachwill project farther than the other, yet the peripheries of both extendbeyond the periphery of the head C. When the rollers D become worn fromuse, or it is desired to move them nearer to or farther away from thecenter of the head, and thus increase or decrease the depth of thethread intended to be cut, it is only necessary to turn the eccentricbushing of the screw-rods a', and thereby cause the rollers to assume acorresponding position.

A standard, C', arises from the table or bed A, and forms a bearing forthe mandrel B, which, at the point where it passes through the bearing,has upon it a screw-thread, b.

The journal is provided with a pin or key, c, passing through an openingtherein, so as to extend -into the grooves comprising the screwthread b.It is -now evident that if the Amandrel B is rotated it will advance orrecede relative to the direction of rotation, and thereby carry theswaging head C correspondingly.

D isa standard arising from one end of the bed and provided with atongue in its lower side fitting into a longitudinal opening, o', in thebed, so as to allow the standard to be readily moved. A small block issecured beneath the tongue and extends beyond the side of the openingo', and is provided with a setscrew, so as to steady and hold standardin place. This standard forms a holder for the sectional female die E,which is let into the upper edge of the standard so as to be flush withthe top and the inner side thereof. This die is of semi'cylindricalform, and has its internal face cut with screw-threads f, whose `pitchand dimensions shall be in accordance with the thread intended to be outin the metal.

A corresponding die, D, is secured to a block, E', which is hinged totheV standard D so as to swing thereon',and the two dies meet and form aperfect die of cylindrical shape, and v of size a little larger than thehead or chuck O,

with the groove of the rollers D almost in contact with the threads f ofthe dies.

. It will be perceived that when the die is.A closed its inner end isopen to receive the chuck C; butthe outer end is entirely' closed andforms a bed against which the blank is to bc placed and rests whilebeing threaded.

The sectional die is prevented from untimely or accidental swingingupward by means of a lock, in the form of an inverted T, passing througha transverse slot in an extension-piece of the standard D', and catchingthereunder when turned, so as to be at right angles with the slot. Byagain turning thelock to register with the slot the block E' is easilyraised and the dies opened. This operation is assisted by a lever, d',which is secured to the top of the vertical part of the lock above theblock E', in which said part is journaled. A pin, e', may pass throughlthe two parts and thus prevent lateral and longitudinal displacement ofthe dies. The sectional dies are retained in place by set-screws and arereadily removable, as also is the chuck C; but both must be firmly heldin place during operation.

F represents the blank-holder,consisting of a flat disk of metal securedto a sliding rod F', which passes entirely through the hollow mandrelB.This rod has its free end cut with screwthreads f', on which are placedtwo nuts, f between which are secured one end of a conncctingbar, G,whose other end is attached to a horizontal rod or shaft G', having itsbearings under the bed or table A or otherwise.

The free end of the shaft G' has connected to it a cord or chain, g,which passes over a pulley, g',at one end ofthe table and is united to atreadle resting on the iioor of the room or workshop. A coil-spring,h,encircles the shaft G' and bears against the the connecting-bar G andthereby draws the sliding rod F' and the blank-holderFin adirection awayfrom the dies E D".

By means of the cord g the bar Gr is drawn toward the dies and therebyforces the blankholder against the bed or closed endof the dies. Inorder that this holder may tit snugly against the chuck C when advancedinto the dies, I construct it in diameter alittle smaller than the chuckC, and form the latter with a ange, so that the holder will iit withinit. A portion of the holder is also cut away and allows the roller D,which projects the farthest, to protrude through the cut-away portionand be flush with the face of the holder.

To the side of the standard A' is secured a bent arm, H, one part ofwhich is slotted, through which passes freely a lever, H', whose lowerend is hinged to a spring or weighted bar or strip, H", attached to thebed or table A.

Near thc upper end of the lever H' is formed a slot, 7L', receiving atappet, I, which projects inwardly, and has the end which enters theslot of smaller size, and provided with a screw and washer, whereby thetappet may be readily adjusted. rl"he free end of the tappet has itsupper inner edge beveled, but its lower side is at to thejunctiou of thebevel.

The strip H" is secured to the table by a set-screw, whereby it can beadjusted as desired. The opposite end has on its under side a pin orlug, i, and is prevented from moving or sliding transversely by an armor guide, j.

J is a rod or arm projecting from the side of the standard A', and haspivoted to it a lever, K, whose upper end is bifurcated or forked, so asto partly straddle a collar, h'. secured to the hollow mandrel B at ornear the end opposite to the chuck C. The collar K' is retained in placeby a set-screw, and is thereby adjustable. 0n this collar is secured asleeve or ring, L, and is provided on its outer periphery with atripping pin or lug, L'.

It will be perceived that if the mandrel D is revolved and advanced itwill carry the collar with it, and thus cause it to approach the tappetI, and when it reaches said tappet, pin L' catches under it, and as itrevolves with the collar it raises the lever H' and strip H", therebyconnecting the pulleys. When the pin has entirely cleared the tappet,the strip H" immediately draws the lever H' in its first position, readyfor the next operation.

M represents a lever pivoted to an arm projecting from the side of thetable beneath the mandrel, or in any other suitable place, and thislever passes under the pin i of the springstrip H", and is turned into ahandle, 7c.

At a point between the handle of the lever and its pivot I secure twoarms, k', one being on each side of the lever and projecting upwardly,and in the space thus formed the lower end ot' the forked lever c has acertain play, which islimited by set-screws on the arms k.

The end of the lever M opposite to its handle has pivoted to it one endof a sliding bar, M', which has its guides in the sides of the table Aand projects on both sides of the table. lts other end receives athumb-screw, l, between which land the table is a coiled spring, m,encircling the bar M.

It is evident that if the handle of the lever be moved in the directionof the dies it will clear the pin t' and the spring-strip H", andimmediately descends, thereby holding the lever and preventing itsreturn.

The coil-spring m, bearin g against the screw l of the sliding bar M',causes the handle end of the lever to press against the pin fi, which isprevented from releasing it by the spring or weighted strip H" holdingit down to its work.

Now, from what has been previously described, it will be seen that ifthe pin L of the collar K' raises the tappet and lever H', the spring H"is likewise raised, and thereby clears the pin i, and at once releasesthe lever M.

As the collar K advances with the mandrel B and reaches the inner forkot' the lever K it moves it and causes the lower end ot' the lever topress against the outer arm k' on the lever, and assists in theoperation of throwing out the lever at the moment it is tripped; butwhen the collar returns and bears against the outer fork of the lever Kthe lower end of this lever presses against the inner arm k', andgradually draws the lever toward the die,

but not past the pint'. These movements are the means by which, afterthe mandrel is advanced, it is automatically returned and then preventedfrom again advancing until the lever M is moved by the hand, and therebycause powerto becommunicatedto the `toothed wheel B' on the mandrel B.In order to accomplish these results I employ an ingenious gearingarrangement, which operates with the parts hitherto described.

At the point where the lever M is pivoted to the sliding bar M',` Ipivotto the {lever'or bar, or secure to the pintle of the joint, an arm, N,which extends upwardly and is connected to a sliding rod,`N', whichpasses through ahollow shaft,`0 mounted on standards, 0', arising fromthe bed or table A. rIhis shaft is prevented from lateral orlongitudinal play` by suitable shoulders or collars.

The upper end ofthe arm Nhas'an opening through which passes one end ofthe rod N', which end is cut with suitable threads. and receives nuts n,one of which is on each side of the top of arm N. When the lever M isoperated the arm N will receive motion therefrom7 and bearingagainst thenuts n will move the rod N' in and out of the hollow shaft O.

On thehollow shaft 0, I secure a collar, P, having a longitudinal slot,o, registering with a similar slot'on the hollow shaft 0. In these slotsa pin, o', is allowed to play, having one end secured to the sliding rodN and the other end connected to a pulley, Q, which is slipped over thecollar P and slides freely thereon to the extent of the play of the pinp in the slots.

When the sliding rod N is drawn in or out of the hollow shaft it willcarry the pulley Q with it. This pulley is constructed of two truncatedcones joined at their bases, or a pulley having its periphery beveledfrom the center to its sides.

On the shaft O, I place two loose pulleys, R R', which are of ordinaryconstruction, except ing that their inner faces are cut away so as toleave a bevel-flange, r, to correspond with the bevel periphery ot thecone-pulley Q. One pulley, R, is prevented from lon gitndinal play inthe direction ofthe dies by its hub ittin g against t the standard O'.The other pulley, It', has no play in the direction of the lever M, byreason of a toothed wheel, S, iirmly secured on the shaft and arrangedclose to the hub of said pulley, with an interposed washer, q, toovercome friction. The toothed wheel S meshes with the toothed wheel Bon the hollow mandrel B, and communicates motion thereto through themedium of the pulleys It R'. These pulleys receive their motion frombelts, or otherwise, and rotate in opposite directions, so that if thecone-pulley is brought against one of the said drivin g-pulleys it'willbe turned in one direction, and if brought against the opposite pulleywill be rotated in the opposite direction, the hollow mandrel (which isro` tated through the medium of the wheels S and B') being caused, byitsscrew-thread bearing on the pin c, to advance or recede according as thecone bears against one or other of the driving-jgiulleys.`

As the wheel B' has a feather fitting a longitudinal groove, b, in theshaft, the latter can slide through the wheel, which is retained initslateral positionlby the standards A'. Should the cone not bearsufciently againstthe loose pulleys, the nuts n mustbe movedaccordingly, so as to regulate the play of the rod N' in the properdirection.

When the lower end of `the forked lever K draws the lever M in thedirection of the die, the cone-pulley@ will brought at a point betweenthe two loose pulleys, and thereby the latter will rotate freely withoutcommunicating power to any other parts of the device.

'This free rotation occurs so soon as the chuck C is entirely withdrawnfrom the die.

The means for accomplishing the above results may be differentlyconstructed and arranged, but it is necessary that they possess all thefeatures described.

The operation is as follows: Power being communicated to the pulleys RR', so as to rotate in opposite directions, the block, E is swung olf ofthe standard D and the blank placed in the die E against its closedside.

The foot is now applied to the treadle, so as to draw the horizontalshaft G', and, through the medium of the connecting-bar G and slidingrod F', to force the blank-holderF against the blank in the die againstthe rest therefor,

where the blank will be held irmly so long as the foot is on thetreadle. The block is swung `back in place and locked as described. rlhelever M is then pushedclear of the pin li on the spring or weightedstrip H". This carries the sliding rod N' in the direction opposite tothe die, and causes the cone-pulley to come in contact with the pulleyB', and thereby communicates power to it in the same direction. Theshaft 0 and toothed wheels S and B' are thus rotated and advance themandrel, running the chuck C into the die. The grooved rollers D nowforce the metal into the threads of the die and cause a correspondingthread to be swaged on the blank. So soon as the chuck has advanced tothe extent desired, the collar K' on the mandrel, having followed it,brings the pin 4 L' against the tappet I, raises it andthe lever H' andthe spring-strip H", thereby tripping the lever M and allowing it to yaway fromv the pin. The spring m on the shaft N' causes the sliding rodN' to move in the direction of the die, and thereby force the conepulleyagainst the pulley B, which immediately communicates its motion to saidcone-pulley and forces the shaft O to rotate in a correspond-v ingdirection, and, through the medium of the wheels S B', to rotate themandrel B, so as to nnserew itself or to recede from the die, andthereby bring the chuck or head Cout of said die. The bevel-edge of thetappet allows the tripping-pin to pass over the tappet, and so soon asthe collar reaches the outer arm of the fork of the lever the lower endof said lever moves toward the inner arm k' on the lever M, andgradually moves the lever M in the direction from whence it has justbeen tripped,

and brings the colle-pulley at a point between tivo pulleys, R R',thereby throwing them out ofgear and stopping therotation of mandrel B.The block E is now unlocked and swung off from the die-holder orstandard D', when the blank, as completely threaded, is withdrawn, readyfor the introduction ot' another blank, after which the block is closedand locked, and the lever M moved to catch under the pin when the deviceis in gear to continue the threading opera-tion. /Vhen larger or smallerarticles are to be threaded the dies and chuck must correspond in sizethereto.

Should a deep or shallow thread be desired the eccentric bushings ofthescrew-rods of the rollers must be moved or turned accordingly.

It will be found that the device is practical and simple in detail andsure in execution.

Having thus described my invention, what l claim as new, and desire tosecure by Letters Patent, is-

1. The mode of swaging threads on sheetnielal ware from the insidethereof', substantiall y as described.

2. The rollers D, chuck G, and sectional die E D", combined andoperating substantially as described.

3. The blank-holder F, in combination with the die, substantially asdescribed.

4. The hollow mandrel B, with screw-threads b' and groove I), andtheWheel B', operating together, substantially as described.

5. The tripping mechanism for the lever M, consisting' ofthe collar K',pin L',lever H', and spring H", or equivalent, substantially asdescribed.

6. The forked lever K, in combination with the collar K' and lever M,substantially as and for the purposedescribed.

7. The means for throwing` the pulleys R lt' in and out of gea-r,consisting of the conical pulley or clutch Q, the hollow shaftO, and thesliding rod N', substantially as described.

8. rlhe eccentric bushings for the rods bearing the sWaging-rollers D,substantially as and for the purpose described.

l). The sectional die, consisting ot the stationary part D' and thehinged part E', in conlbination With tlieadvancing and receding chuck C,substantially as described.

l0. The combination of the various parts, substantially as described,for the purpose specified.

To the above I have signed my naine this 3d day of December, 1867.

THOMAS HOUGHTON.

